Method of manufacturing SOI wafer

Abstract

A method of manufacturing an SOI wafer, including (a) forming a thermal oxide film on an SOI layer of an SOI wafer by a heat treatment under an oxidizing gas atmosphere, (b) measuring thickness of the SOI layer after forming the thermal oxide film, (c) performing a batch cleaning, wherein an etching amount of SOI layer is adjusted depending on thickness of the SOI layer measured in step (b) such that thickness of the SOI layer is adjusted to be thicker than a target value after etching, (d) measuring thickness of the SOI layer after batch cleaning, (e) performing a single-wafer cleaning, wherein an etching amount of the SOI layer is adjusted depending on thickness of the SOI layer measured in step (d) such that thickness of the SOI layer is adjusted to be the target value after etching, and removing the thermal oxide film formed in step (a) before or after step (b).

The invention claimed is: 
     
       1. A method of manufacturing an SOI wafer, including reducing a thickness of an SOI layer formed on an insulator layer of an SOI wafer to a predetermined thickness such that the thickness of the SOI layer becomes a target value, the method comprising at least the steps of:
 (a) forming a thermal oxide film on the SOI layer by a heat treatment under an oxidizing gas atmosphere; 
 (b) measuring the thickness of the SOI layer after forming the thermal oxide film; 
 (c) performing batch cleaning which includes immersing the SOI layer in a cleaning solution having an etching property with respect to the SOI layer, wherein an etching amount of the SOI layer is adjusted depending on the thickness of the SOI layer measured in the step (b) such that the thickness of the SOI layer is adjusted to be thicker than the target value after etching by the batch cleaning; 
 (d) measuring the thickness of the SOI layer after the batch cleaning; and 
 (e) performing single-wafer cleaning which includes immersing the SOI layer in a cleaning solution having an etching property with respect to the SOI layer, wherein an etching amount of the SOI layer is adjusted depending on the thickness of the SOI layer measured in the step (d) such that the thickness of the SOI layer is adjusted to be the target value after etching by the single-wafer cleaning, the method further comprising 
 removing the thermal oxide film formed in the step (a) after the step (a) and before the step (b), or after the step (b) and before the step (c). 
 
     
     
       2. The method of manufacturing an SOI wafer according to  claim 1 , wherein the thickness is measured in the step (b) without removing the thermal oxide film formed in the step (a), the thermal oxide film formed in the step (a) is removed by batch cleaning with a HF-containing aqueous solution after the step (b) and before the step (c), and the batch cleaning in the step (c) is performed by immersing the SOI layer in the cleaning solution having the etching property with respect to the SOI layer without drying a surface of the SOI layer after removing the thermal oxide film. 
     
     
       3. The method of manufacturing an SOI wafer according to  claim 1 , wherein the SOI wafer is produced by an ion implantation delamination method which includes at least the steps of: bonding a bond wafer having a micro bubble layer formed by implanting ions and a base wafer serving as a supporting substrate; and delaminating the bond wafer along the micro bubble layer to form a thin film on the base wafer. 
     
     
       4. The method of manufacturing an SOI wafer according to  claim 2 , wherein the SOI wafer is produced by an ion implantation delamination method which includes at least the steps of: bonding a bond wafer having a micro bubble layer formed by implanting ions and a base wafer serving as a supporting substrate; and delaminating the bond wafer along the micro bubble layer to form a thin film on the base wafer. 
     
     
       5. The method of manufacturing an SOI wafer according to  claim 1 , wherein the batch cleaning and the single-wafer cleaning include immersion in an SC1 solution. 
     
     
       6. The method of manufacturing an SOI wafer according to  claim 2 , wherein the batch cleaning and the single-wafer cleaning include immersion in an SC1 solution. 
     
     
       7. The method of manufacturing an SOI wafer according to  claim 3 , wherein the batch cleaning and the single-wafer cleaning include immersion in an SC1 solution. 
     
     
       8. The method of manufacturing an SOI wafer according to  claim 4 , wherein the batch cleaning and the single-wafer cleaning include immersion in an SC1 solution. 
     
     
       9. The method of manufacturing an SOI wafer according to  claim 1 , wherein a batch average of the thickness of the SOT layer after the batch cleaning in the step (c) is controlled to be a value between the target value and the target value+0.5 nm. 
     
     
       10. The method of manufacturing an SOI wafer according to  claim 2 , wherein a batch average of the thickness of the SOT layer after the batch cleaning in the step (c) is controlled to be a value between the target value and the target value+0.5 nm. 
     
     
       11. The method of manufacturing an SOI wafer according to  claim 3 , wherein a batch average of the thickness of the SOT layer after the batch cleaning in the step (c) is controlled to be a value between the target value and the target value+0.5 nm. 
     
     
       12. The method of manufacturing an SOI wafer according to  claim 4 , wherein a batch average of the thickness of the SOT layer after the batch cleaning in the step (c) is controlled to be a value between the target value and the target value+0.5 nm. 
     
     
       13. The method of manufacturing an SOI wafer according to  claim 5 , wherein a batch average of the thickness of the SOT layer after the batch cleaning in the step (c) is controlled to be a value between the target value and the target value+0.5 nm. 
     
     
       14. The method of manufacturing an SOI wafer according to  claim 6 , wherein a batch average of the thickness of the SOT layer after the batch cleaning in the step (c) is controlled to be a value between the target value and the target value+0.5 nm. 
     
     
       15. The method of manufacturing an SOI wafer according to  claim 7 , wherein a batch average of the thickness of the SOI layer after the batch cleaning in the step (c) is controlled to be a value between the target value and the target value+0.5 nm. 
     
     
       16. The method of manufacturing an SOI wafer according to  claim 8 , wherein a batch average of the thickness of the SOI layer after the batch cleaning in the step (c) is controlled to be a value between the target value and the target value+0.5 nm.